Re: [PATCH] Input: elan_i2c: Disable irq on shutdown

On Wed, Jun 02, 2021 at 11:13:40PM -0700, Stephen Boyd wrote:

Quoting Dmitry Torokhov (2021-06-02 21:33:41)

quoted

On Wed, Jun 02, 2021 at 06:33:49PM -0700, Stephen Boyd wrote:

quoted

Quoting Dmitry Torokhov (2021-06-02 18:18:17)

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I do not think keeping counter balanced would be important here, as we
are shutting down, and upon reboot everything will be reinitialized from
scratch. Also, we are lucky in that there is just a handful of I2C
drivers defining shutdown() methods.

quoted

Please don't make me shave this yak.

I'm afraid someone has to... I'm adding Wolfram to CC to get his take on
this.

I suppose another option would be to introduce some common function that
i2c drivers can use for their shutdown op, like i2c_generic_shutdown()
that would disable the irq? I would guess that it isn't a great idea to
blanket disable the irq in case some i2c driver wants to do something
that may require that irq to come in once more during shutdown to signal
that things are off or something like that.

Would having this common function that this driver opts into work for
you?

Opting in in this fashion will still require changes in the majority
of drivers (any I2C touchscreen or touchpad may be touched while system
is being shut down, so all of them will need to have interrupt freed or
disabled, or they may initiate I2C transfer). How about something like
this;

Yes, this approach should work. I assume a device that doesn't have a
shutdown function will be happy to let the i2c core disable the irq for
it so it looks low risk.

Will you send a proper patch to Wolfram or would you like me to wrap it
up and resend?

If you could do that I'd be more than happy.

Thanks.

-- 
Dmitry